My son's scooter has started sputtering when he tries to go full throttle. If he does it gradually it won't do it. However, top speed is only 17 km per hr. He's done a full 8 hr charge on it with no change.
The Razor EcoSmart electric scooter has an XLR charger port which makes load testing the battery pack very easy. The multimeter probes can be inserted directly into the charger port's top two holes for testing.